The Effect Of Vitamin A Supplementation On Thyroid Function In Premenopausal Women

paymanz · Mar 8, 2015

http://www.ncbi.nlm.nih.gov/pubmed/23378454

Abstract
OBJECTIVE:

Vitamin A and its retinoid derivates play an important role in regulation of normal growth and development. Vitamin A has been shown to regulate thyroid hormone metabolism and inhibit thyroid-stimulating hormone (TSH) secretion via down regulation of TSH-β gene expression; however, the effect of vitamin A on thyroid function in obese individuals who are at higher risk of subclinical hypothyroidism is still unclear. In the present study we investigate the impact of vitamin A supplementation on thyroid function in obese women.
METHOD:

A 4-month randomized, double blind controlled trial was conducted among 84 healthy women aged 17-50 years old: 56 were obese (body mass index [BMI] 30-35 kg/m(2)) and 28 were nonobese (BMI 18.5-24.9 kg/m(2)). Obese women were randomly allocated to receive either vitamin A (25,000 IU/d retinyl palmitate) or placebo. Nonobese women received vitamin A. At baseline and 4 months after intervention, serum concentrations of TSH, total thyroxine (T4), total triiodothyronine (T3), retinol-binding protein (RBP), and transthyretin (TTR) were measured.
RESULTS:

Baseline concentrations of thyroid hormones, RBP and TTR were not significantly different between groups. Vitamin A caused a significant reduction in serum TSH concentrations in obese (p = 0.004) and nonobese (p = 0.001) groups. Serum T3 concentrations also increased in both obese and nonobese vitamin A-treated groups (p < 0.001). Serum T4 decreased in all 3 groups after treatment. The results showed a significant reduction in serum RBP in the obese group after vitamin A supplementation (p = 0.007), but no significant change was seen in serum TTR.
CONCLUSIONS:

Serum TSH concentrations in vitamin A-treated subjects were significantly reduced; therefore, vitamin A supplementation might reduce the risk of subclinical hypothyroidism in premenopausal women.

haidut · Mar 8, 2015

paymanz said:
http://www.ncbi.nlm.nih.gov/pubmed/23378454

Abstract
OBJECTIVE:

Vitamin A and its retinoid derivates play an important role in regulation of normal growth and development. Vitamin A has been shown to regulate thyroid hormone metabolism and inhibit thyroid-stimulating hormone (TSH) secretion via down regulation of TSH-β gene expression; however, the effect of vitamin A on thyroid function in obese individuals who are at higher risk of subclinical hypothyroidism is still unclear. In the present study we investigate the impact of vitamin A supplementation on thyroid function in obese women.
METHOD:

A 4-month randomized, double blind controlled trial was conducted among 84 healthy women aged 17-50 years old: 56 were obese (body mass index [BMI] 30-35 kg/m(2)) and 28 were nonobese (BMI 18.5-24.9 kg/m(2)). Obese women were randomly allocated to receive either vitamin A (25,000 IU/d retinyl palmitate) or placebo. Nonobese women received vitamin A. At baseline and 4 months after intervention, serum concentrations of TSH, total thyroxine (T4), total triiodothyronine (T3), retinol-binding protein (RBP), and transthyretin (TTR) were measured.
RESULTS:

Baseline concentrations of thyroid hormones, RBP and TTR were not significantly different between groups. Vitamin A caused a significant reduction in serum TSH concentrations in obese (p = 0.004) and nonobese (p = 0.001) groups. Serum T3 concentrations also increased in both obese and nonobese vitamin A-treated groups (p < 0.001). Serum T4 decreased in all 3 groups after treatment. The results showed a significant reduction in serum RBP in the obese group after vitamin A supplementation (p = 0.007), but no significant change was seen in serum TTR.
CONCLUSIONS:

Serum TSH concentrations in vitamin A-treated subjects were significantly reduced; therefore, vitamin A supplementation might reduce the risk of subclinical hypothyroidism in premenopausal women.

I think equally as important was the increase in T3 and reductions in T4. So, vitamin A somehow increased the conversion of T4 into T3, which suggests that it was beneficial to liver function. I need to see the study to gauge how much TSH dropped. If it dropped below 1, then vitamin A may be a good substitute for thyroid supplementation since I am not convinced people without actual thyroid disease need to take hormone replacement therapy.
Thanks for the find.

paymanz · Mar 8, 2015

haidut said:
I think equally as important was the increase in T3 and reductions in T4. So, vitamin A somehow increased the conversion of T4 into T3, which suggests that it was beneficial to liver function. I need to see the study to gauge how much TSH dropped. If it dropped below 1, then vitamin A may be a good substitute for thyroid supplementation since I am not convinced people without actual thyroid disease need to take hormone replacement therapy.
Thanks for the find.

yeah but they used a heavy dose in the study.i know peat says he has taken 50,000 in some periods(summer), but taking that dosage in long term dosent have the risk of bone loss?
i personally prefer to stay in the safe 4000-5000 iu/d dose and from liver.
here is another study
The interrelationship of thyroid hormones with vitamin A and zinc nutritional status in patients with chronic hepatic and gastrointestinal disorders. - PubMed - NCBI

haidut · Mar 8, 2015

paymanz said:
haidut said:

I think equally as important was the increase in T3 and reductions in T4. So, vitamin A somehow increased the conversion of T4 into T3, which suggests that it was beneficial to liver function. I need to see the study to gauge how much TSH dropped. If it dropped below 1, then vitamin A may be a good substitute for thyroid supplementation since I am not convinced people without actual thyroid disease need to take hormone replacement therapy.
Thanks for the find.

Click to expand...

yeah but they used a heavy dose in the study.i know peat says he has taken 50,000 in some periods, but taking that dosage in long term dosent have the risk of bone loss?
i personally prefer to stay in the safe 4000-5000 iu/d dose and from liver.
here is another study
http://www.ncbi.nlm.nih.gov/pubmed/7196691

I would not call 25,000 IU a high dose. That used to be about the recommended RDA (20,000 IU) and in some countries still is. The FDA lowered the RDA for vitamin A to 5,000 IU for reasons that are beyond me to understand. Also, if you are taking it with vitamin D then it probably poses even less risk. If vitamin A was that dangerous to bones, all acne patients taking Accutane would have fallen apart by now.

paymanz · Mar 8, 2015

haidut said:
I would not call 25,000 IU a high dose. That used to be about the recommended RDA (20,000 IU) and in some countries still is. The FDA lowered the RDA for vitamin A to 5,000 IU for reasons that are beyond me to understand. Also, if you are taking it with vitamin D then it probably poses even less risk. If vitamin A was that dangerous to bones, all acne patients taking Accutane would have fallen apart by now.

which countries?
some accutane users have bone problems.i agree with you that with more vitamin D probably we can take more vit A.i just remember that i read studies showing that more than 5k is bad for bones.maybe their vit D levels was not good.
dave aspery also recommend 10-15k and with vit D.higher A higher D...
i would like to know what dr peat think about this.

haidut · Mar 9, 2015

paymanz said:
haidut said:

I would not call 25,000 IU a high dose. That used to be about the recommended RDA (20,000 IU) and in some countries still is. The FDA lowered the RDA for vitamin A to 5,000 IU for reasons that are beyond me to understand. Also, if you are taking it with vitamin D then it probably poses even less risk. If vitamin A was that dangerous to bones, all acne patients taking Accutane would have fallen apart by now.

Click to expand...

which countries?
some accutane users have bone problems.i agree with you that with more vitamin D probably we can take more vit A.i just remember that i read studies showing that more than 5k is bad for bones.maybe their vit D levels was not good.
dave aspery also recommend 10-15k and with vit D.higher A higher D...
i would like to know what dr peat think about this.

I think Russia and Japan have higher RDA for vitamin A. As far as ratio of A to D, most studies I have seen claim the "optimal" ratio is 5:1 for A

. But this could easily be different for every one since it would depend on current vitamin status and tolerance, etc. Maybe not a bad idea to get vitamin levels checked before supplementing.

Waremu · Mar 9, 2015

What is interesting about this study is that obese subjects were given a dosage of Vitamin A which, by Ray Peats standards, would probably be considered too high.

Ray Peat has constantly said that the average hypothyroid person needs roughly around 5000IU (maybe a bit more, like 8000-10000IU in some cases) and, in most cases, do not want to take very much more because it will cause more harm than good by being anti-thyroid. I noticed this was also the case for me when I first began following his work and putting it into practice.

However, this study seems to show that these obese subjects saw an increase in thyroid would would normally be considered high for them, which then would bring us to the question: do we know enough to say that most obese/hypothyroid (if someone is obese they are hypothyroid) people do not need much more Vitamin A than previously thought? Possibly, most hypothyroid (if diet is right) may actually need more Vitamin A. Maybe they are more deficient in Vitamin A than we thought.

Very interesting indeed.

tara · Mar 9, 2015

Regarding the study, does it mention the start and end months, and approximate location? If not, and depending on when and where, seasonal effects could be a possible confounder?

Waremu said:
obese/hypothyroid (if someone is obese they are hypothyroid)

Do we know this? It may be common, but I'm not sure that I've seen it demonstrated that it always applies. Some obese people seem to be metabolically reasonably healthy.

Peata · Mar 10, 2015

I started taking 15,0000 iu Vitamin A yesterday. I've had it around but was reluctant to take it for various reasons. But I am going to do it at least for a while. I have already been taking Vitamin D and magnesium, whatever E is in Progest E, and Vitamin K2.

schultz · Mar 10, 2015

haidut said:
I think equally as important was the increase in T3 and reductions in T4. So, vitamin A somehow increased the conversion of T4 into T3, which suggests that it was beneficial to liver function. I need to see the study to gauge how much TSH dropped. If it dropped below 1, then vitamin A may be a good substitute for thyroid supplementation since I am not convinced people without actual thyroid disease need to take hormone replacement therapy.
Thanks for the find.

Estrogen disrupts liver function and vitamin A is anti-estrogenic, so maybe the vitamin A is lowering estrogen and allowing the liver to convert more T4->T3. More T3 would lower the TSH.

Peata · Mar 12, 2015

Peata said:
I started taking 15,0000 iu Vitamin A yesterday. I've had it around but was reluctant to take it for various reasons. But I am going to do it at least for a while. I have already been taking Vitamin D and magnesium, whatever E is in Progest E, and Vitamin K2.

After taking it two days I wondered if my liver could handle it. No side effect, just things I read had me a little worried. I took yesterday off and today started using the whole capsule on my skin today. Hands, face, neck, chest. Thought it might be safer since I would absorb less. These are gel capsules, I can't just put it in the pill splitter and save half for the next day.

Peata · Mar 12, 2015

Peata said:
Peata said:

I started taking 15,0000 iu Vitamin A yesterday. I've had it around but was reluctant to take it for various reasons. But I am going to do it at least for a while. I have already been taking Vitamin D and magnesium, whatever E is in Progest E, and Vitamin K2.

Click to expand...

After taking it two days I wondered if my liver could handle it. No side effect, just things I read had me a little worried. I took yesterday off and today started using the whole capsule on my skin today. Hands, face, neck, chest. Thought it might be safer since I would absorb less. These are gel capsules, I can't just put it in the pill splitter and save half for the next day.

I'm also taking 2 vitamin E capsules daily since Tues.

tara · Mar 14, 2015

I've shifted OT discussion of obesity between Waremu and I to a separate thread here:

viewtopic.php?f=11&t=6156&p=72443#p72443

haidut · Oct 14, 2015

[moderator edit: same study posted twice, threads merged]

The reason I titles the post this way is that the effects of vitamin A supplementation parallel the effects of supplementing T3 - i.e. lower TSH and T4 and higher T3 levels. Some people who shy away from vitamin A due to Ray cautioning against its use due to its purported thyroid-inhibiting effects. I don't know if Ray had some dose in mind to achieve this negative effect, but this study found the exact opposite. Vitamin A lowered TSH and increased T3 in both lean and obese humans. Given that obese people are very likely hypothyroid, this underscores the positive effects of vitamin A even on thyroid function of compromised metabolism/health. The dose used was not that high (25,000 IU daily for 4 months) but it is still 6 times higher than the RDA.

http://www.ncbi.nlm.nih.gov/pubmed/23378454

"...RESULTS: Baseline concentrations of thyroid hormones, RBP and TTR were not significantly different between groups. Vitamin A caused a significant reduction in serum TSH concentrations in obese (p = 0.004) and nonobese (p = 0.001) groups. Serum T3 concentrations also increased in both obese and nonobese vitamin A-treated groups (p < 0.001). Serum T4 decreased in all 3 groups after treatment. The results showed a significant reduction in serum RBP in the obese group after vitamin A supplementation (p = 0.007), but no significant change was seen in serum TTR.
CONCLUSIONS: Serum TSH concentrations in vitamin A-treated subjects were significantly reduced; therefore, vitamin A supplementation might reduce the risk of subclinical hypothyroidism in premenopausal women."

Giraffe · Oct 14, 2015

I found another abstract from the same study. The table is interesting.

Agent207 · Oct 14, 2015

Is it needed to divide the dose daily? I mean, if I eat 200,000IU liver equivalent per week, is it OK if I split the total intake twice a week?

I've been eating about 10oz. per week of calf liver.

haidut · Oct 14, 2015

Agent207 said:
post 104199 Is it needed to divide the dose daily? I mean, if I eat 200,000IU liver equivalent per week, is it OK if I split the total intake twice a week?

I've been eating about 10oz. per week of calf liver.

I think with the fat solubles you can take only 1-2 times a week. So, eating liver once a week or once every two weeks is fine. Ray said he takes the fat solubles only occasionally and topically.

Sea · Oct 14, 2015

This makes sense to me, as I have been taking around 150k IU/day for a couple weeks now and I have had to stop taking aspirin and greatly lower my dosages of thyroid and caffeine to keep from going too hyperthyroid. I will note that when my temps and pulse weren't as high, even 25k IU would cause some hypothyroid symptoms, but now that I have been getting a lot of red light and taking a lot of caffeine even when I have gone as high as 250k IU in a day I don't notice any drop in temp/pulse.

haidut · Oct 14, 2015

Giraffe said:
post 104198 I found another abstract from the same study. The table is interesting.

Wow, those are pretty substantial changes from such a low dose. I wonder what happens at the higher doses. Maybe the disappearance of acne and the anti-cancer effects of vitamin A are really result of greatly improved metabolism rather than something directly hormonal. I posted some studies on vitamin A being anti-estrogenic and dopaminergic, both of which match well the pro-thyroid effects.

charlie · Oct 14, 2015

Giraffe said:
post 104198 I found another abstract from the same study. The table is interesting.

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The Effect Of Vitamin A Supplementation On Thyroid Function In Premenopausal Women

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